You have to host them outside of The Realm. Then you can include links (inline links, etc.) for as many pictures per post as you want. Hosting them via The Realm restricts you to three per post.

Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson

If you can, you'd probably just do the inline links manually [img]photo[/img] - etc. You can't attach files via PM.

Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson